Ion beam mixing of Ti-TiN multilayers for tribological and corrosion protection

The present paper reports the changes on the tribological and corrosion protection properties of Ti-TiN thin film multilayered structures exposed to 4 MeV Si+ ion bombardment. The starting Ti-TiN multilayers used in this study had a periodic thickness ratio from 0.5 (50 nm/100 nm Ti/TiN) to 2 (100 nm/50 nm Ti/TiN) deposited by magnetron sputtering. The ion beam mixing was accomplished by relatively low doses and current irradiation. The structure and phase formation were derived from Rutherford backscattering (RBS) and X-ray diffraction (XRD). The potential of corrosion protection was evaluated by potentiodynamic electrochemical methods. The coating protection power was compared with the non-bombarded samples, with Ti/TiN multilayers with gradient interfaces and with samples deposited by ion beam assisted deposition (IBAD). The results show that the ion beam mixed samples present a long-term corrosion protection power expressively better than the as deposited multilayers with a small decrease of its hardness. (C) 2001 Elsevier Science B.V. All rights reserved.